Technical Field
The present invention relates to semiconductor fabrication, and more particularly to the fabrication of a low-K spacer for replacement metal gate fin field effect transistor.
Description of the Related Art
The replacement metal gate (RMG) fin field effect transistor (finFET) fabrication process typically includes first patterning the gate, followed by conformal spacer deposition, spacer etch, and then source/drain epitaxial merge. However, the spacer etch step can introduce both fin erosion in the source/drain area and also top corner rounding of the dummy gate hard mask. Source/drain fin erosion raises fin epitaxial merge concerns. Gate hard mask top corner rounding can potentially cause epitaxial nodules at source/drain epitaxial merge.